Heat activated ballistic blocker

An apparatus for use in a wellbore to prevent an igniter from igniting a pyrotechnic device within a downhole well tool until after said downhole well tool is disposed downhole within said wellbore, said apparatus comprising:

• a housing having an ignition pathway extending therein, through which said igniter reacts for igniting said pyrotechnic device;
• a blocking member which is movable between a plurality of positions for selectably obstructing said ignition pathway to prevent said igniter from igniting said pyrotechnic device;
• and
• an actuator for lowering downhole within said wellbore with said downhole well tool and heating to an activation temperature, at which said actuator rotates said blocking member from a blocking position obstructing said ignition pathway to an ignition position for allowing said igniter to ignite said pyrotechnic device.

An apparatus for use in a wellbore to prevent an igniter from igniting a power charge within a wellbore pressure setting assembly until after said wellbore pressure setting assembly is disposed downhole within said wellbore, said apparatus comprising:

• a tubular housing having a passageway extending longitudinally therein, said passageway providing an ignition pathway through which said igniter reacts for igniting said power charge within said wellbore pressure setting assembly.
• a blocking member which is movable between a plurality of positions for selectably obstructing said passageway to block said ignition pathway and prevent said igniter from igniting said power charge;
• and
• an actuator for lowering downhole within said wellbore with said wellbore pressure setting assembly and heating to an activation temperature, at which said actuator moves said blocking member from a blocking position obstructing said passageway to an ignition position for allowing said igniter to ignite said power charge.

An apparatus for use in a wellbore to prevent an igniter from igniting a power charge within a wireline pressure setting assembly until after said wireline pressure setting assembly is disposed downhole within said wellbore, said apparatus comprising:

• a tubular housing having a passageway extending longitudinally therein, said passageway providing an ignition pathway through which said igniter reacts for igniting said power charge within said wireline pressure setting assembly,
• a valve plug which is movable for rotating between a plurality of positions for selectably obstructing said passageway to block said ignition pathway and prevent said igniter from igniting said power charge;
• and
• a torsion member formed from a shape memory metal for lowering downhole within said wellbore with said wireline pressure setting assembly and exposing to downhole wellbore temperatures, which heat said torsion member to an activation temperature at which said torsion member rotates said valve plug from a blocking position obstructing said passageway to an ignition position for allowing said igniter to ignite said power charge.

A method for preventing an igniter from igniting a pyrotechnic device within a downhole well tool until after said downhole well tool is disposed downhole within a wellbore, said method comprising the steps of:

• securing a housing to a downhole well tool so that a passageway extending longitudinally within said tubular housing extends between said igniter and said pyrotechnic device;
• obstructing said passageway with a blocking member for preventing said igniter from igniting said pyrotechnic device;
• providing an actuator which is operable for moving said blocking member between a plurality of positions;
• lowering said wellbore pressure setting assembly and said housing downhole within said wellbore;
• and
• heating said actuator to substantially an activation temperature, at which said actuator moves said blocking member from a position obstructing said passageway to a position for allowing said igniter to ignite said pyrotechnic device.

A method for preventing an igniter from igniting a pyrotechnic device within a downhole well tool until after said downhole well tool is disposed downhole within a wellbore, said method comprising the steps of:

• securing a housing to a downhole well tool so that a passageway extending longitudinally within said tubular housing extends between said igniter and said pyrotechnic device;
• obstructing said passageway with a blocking member for preventing said igniter from igniting said pyrotechnic device;
• providing an actuator which is operable for moving said blocking member between a plurality of positions;
• lowering said wellbore pressure setting assembly and said housing downhole within said wellbore;
• and
• exposing said actuator to downhole wellbore temperatures, which heat said actuator to substantially an activation temperature, at which said actuator rotates said blocking member from a position obstructing said passageway to a position for allowing said igniter to ignite said pyrotechnic device.

A method for preventing an igniter from igniting a power charge within a wellbore pressure setting assembly until after said wellbore pressure setting assembly is disposed downhole within a wellbore, said method comprising the steps of:

• securing a tubular housing to a wellbore pressure setting assembly so that a passageway extending longitudinally within said tubular housing extends between said igniter and said power charge;
• obstructing said passageway with a blocking member for preventing said igniter from igniting said power charge;
• providing an actuator which is operable for moving said blocking member between a plurality of positions;
• lowering said wellbore pressure setting assembly and said housing downhole within said wellbore;
• and
• heating said actuator to substantially an activation temperature, at which said actuator operates to move said blocking member from a position obstructing said passageway to a position for allowing said igniter to ignite said power charge.